Site-made trusses vs. pre-manufactured trusses: The Facts!

Site-made roof trusses are either hand made timber roof trusses connected with bolts and nails OR site application nail plates at the node points.

Pre-manufactured trusses are pre-manufactured timber roof trusses based on SANS 10243 and connected with engineering system provided nail plates as per design.

Site-made trusses would have had to, as a rational design, be designed by a registered Professional Competent Person. Girders for hips & valleys must be designed by an Engineer before manufacturing.

Pre-manufactured trusses are designed using the Engineering Software from one of the 4 accredited system members of the ITC-SA: Alpine Automation; International Truss Systems; MiTek Industries and Multinail South Africa.

Both site-made and pre-manufactured trusses have to be inspected for compliance with Regulation A19 of the National Building Regulations, the Design intent and specific regulations and specifications related to Timber Roof Trusses, where a Registered Professional Person as per the Engineering Council South Africa will take liability for the said structure.Once complying as per the Engineer, a Certificate of Compliance will be issued that will allow the owner to obtain an occupancy Certificate from the Local Municipality.

Statistics obtained by the Institute for Timber Construction South Africa show that 90% of site-made trusses do not comply with the relevant regulations and specifications as required by the National Building Regulations. This includes no rational designs and the use of non-structural timber members. They are found to be around ±20% more expensive than pre-manufactured timber roof trusses. Should there be any queries, you will generally have no avenue for remedy and will end in tedious and costly civil litigation! Any savings that your builder may have wrongly advised you of will be negated many times over!!

If these pre-manufactured trusses are erected by an accredited ITC-SA Roof Erector, you are guaranteed a roof structure that complies 100% and you have the peace of mind that, should you have any queries, there is an avenue for remedy via the ITC-SA’s disciplinary procedures for all its accredited members.

View the detailed PDF outlining the differences and similarities between site-made roof trusses and pre-manufactured roof trusses

Previous story
keyboard_arrow_upCorobrik-SAIA Awards of Merit and Awards for Excellence in Architecture
keyboard_arrow_downCorobrik-SAIA Awards of Merit and Awards for Excellence in Architecture

The Corobrik-SAIA Awards of Merit and Awards for Excellence 2010 were presented recently at a ceremony at the City Hall in Johannesburg, as part of the architectural festival AZA 2010.  Since 1990, the biennial Awards for Excellence programme has signalled the highest accolades from the South African Institute of Architects (SAIA), acknowledging the achievements of its members in the design and delivery of projects that

Next story
keyboard_arrow_upErosion solutions
keyboard_arrow_downErosion solutions

The versatility and durability of EnviroRock's geocontainers provides solutions to structures such as walls, groynes, reef structures, flow control structures and other applications In marine and inland

keyboard_arrow_upa.b.e. products for two Western Cape floor refurbishments
keyboard_arrow_downa.b.e. products for two Western Cape floor refurbishments

a.b.e. Construction Chemicals supplied products for the upgrading of the flooring at two premises in the Western Cape: the Supa Quick tyre and fitment centre in Robertson, and Sea Harvest fish processing facilities at Saldanha Bay. Products used abescreed SLC P; abecote primer; and abecote 441.

keyboard_arrow_upInteresting background to Sun Arena Menlyn Maine
keyboard_arrow_downInteresting background to Sun Arena Menlyn Maine

Time Square Sun Arena was the Commercial Category Winner at the recent Steel Awards. What’s interesting is that the original project wasn’t envisaged in steel but in concrete. For practical reasons, this was later changed to steel. Read on to find out more. The Sun Arena at Time Square in Menlyn Maine is the biggest […]

keyboard_arrow_upAttack-proof access cubicle protects bank
keyboard_arrow_downAttack-proof access cubicle protects bank

This one of a kind Cylindrical Access Cubicle was designed, engineered and installed by Boomgate Systems. Installed in a bank to an “Attack Proof” rating of ARL-1, it is the first and only installation of this type. Based on the humidity and the proximity to the ocean the entire cubicle was constructed using 316-grade stainless […]